In a conventional hinge assembly or arrangement disposed between a wing or a lifting foil and its associated elongated controllable flap surfaces, the flap surfaces are supported by two or more hinges which are mounted between the foil and the flap surfaces. In many applications, the elongated flap surfaces are segmented or sectionalized into a plurality of sections in order to prevent binding of the hinges, particularly in the center portion of the flap surfaces, due to bending loads which are experienced during flight. These flap sections are interconnected so that a universal pivotal movement of the complete flap structure may be effectuated. Since each section is supported by at least two or more hinge assemblies a number of undesirable stress concentrations are experienced at fastener holes of the hinge assemblies requiring a manufacturing process dictating precise and accurate tolerances.
Also, if the axis of the hinge is close to or parallel to the foil skin, either at the upper or lower foil skin surface, a beefed up structure of a bulging structure is needed at the skin side to enable a specific rotating arc of the flap surface. Such an extended bulge or mounting is undesirable from a drag viewpoint.
It will be evident, therefore, that an elimination of a number of hinges would be economical and would reduce the stress concentration points, drag, and maintenance and inspection time associated with the hinge assembly.